Rockford Fosgate P2D4-12

• Sensitivity (1W, 1m, infinite baffle) SPL1W 86.6dB

Thiele & Small parameters

• Resonance frequency (free air) fS 27.2Hz
• Mechanical quality factor QMS 6.30
• Electrical quality factor QES 0.59
• Total quality factor QTS 0.54

Large signal parameters

• Maximum linear excursion xmax 13.3mm
• Air volume displaced at xmax VD 758cm³
• Power handling P 400W
• Program power Pmax 800W

Voice Coil

• Nominal impedance Z 2 x 4Ω
• DC resistance (in series) RE 6.4Ω
• Inductance (1kHz, in series) LE 5.5mH
• VC Diameter 57mm

Magnet

• Force factor (in series) Bl 18.9N/A
• Motor constant Bl/√RE 7.47N/√W
• Weight 2.06kg

Diaphragm

• Effective diameter 269mm
• Effective area SD 570cm²
• Moving mass MMS 193g
• Moving mass (without air load) MMD 184g

Suspensions

• Stiffness KMS 5.65N/mm
• Compliance CMS 177µm/N
• Equivalent volume to the compliance VAS 81.5L
• Mechanical resistance RMS 5.25N·s/m

Dimensions

• Nominal diameter 12″
• 305mm
• Baffle cutout diameter 285mm
• Mounting depth 162mm
• Volume occupied by the driver 2.41L